Inhaled NO (iNO) has been shown to have beneficial effects on decreasing pulmonary inflammation, increasing function of surfactant and improving lung growth in prematurely born animal models. iNO has been gradually applied in the neonatal intensive care unit since its first use for persistent pulmonary hypertension (PPHN) in the early 1990's. Although many research findings have shown the benefits of iNO for hypoxic respiratory failure (HRF) of preterm infants, there is no certain evidence to support the routine use of iNO in premature infants. According to recent literature, the mechanism of iNO therapy, treatment scheme, iNO effectiveness and safety in premature infants were reviewed in this article, so as to provide bases for the clinical use of this treatment.